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电容降压式电源变换器设计与计算详解

通信电源技术 2021年第10期38卷 36-39页

作者：傅璐璐赵洪许增信刘礼进丽水职业技术学院浙江丽水323000 浙江华鑫起重机械有限公司浙江松阳323004

串联电容降压式电源变换电路具有成本低和体积小等优点,在0.5~1 W的小功率低压稳压电源中应用较广,但部分厂家在电路设计与计算上对其原理把握不够准确,导致产品故障率较高。在分析电容降压稳压原理的基础上提出详细的设计与计算方法,... 详细信息

串联电容降压式电源变换电路具有成本低和体积小等优点,在0.5~1 W的小功率低压稳压电源中应用较广,但部分厂家在电路设计与计算上对其原理把握不够准确,导致产品故障率较高。在分析电容降压稳压原理的基础上提出详细的设计与计算方法,经过工程运用实践证明设计思路正确且计算可靠,特别是在极限情况下确保了电路的安全。

关键词：电源变换稳定电源参数计算

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一种汽车洗涤水壶的固定结构

汽车实用技术 2018年第10期44卷 86-87页

作者：陆圣君付永娜吴露露王亮刘睿安徽江淮汽车集团股份有限公司安徽合肥230000

汽车洗涤水壶用来存储洗涤液,用于汽车前挡风玻璃和某些车型前大灯面罩的日常清洗,给驾驶者提供一个清晰、明亮的视野,保证驾驶员的行车安全。文章详细阐述了一种汽车洗涤水壶的固定结构,在受到发动机舱布置和车身钣金的约束时,保证其... 详细信息

汽车洗涤水壶用来存储洗涤液,用于汽车前挡风玻璃和某些车型前大灯面罩的日常清洗,给驾驶者提供一个清晰、明亮的视野,保证驾驶员的行车安全。文章详细阐述了一种汽车洗涤水壶的固定结构,在受到发动机舱布置和车身钣金的约束时,保证其安装的可靠性。

关键词：洗涤水壶车身钣金固定结构

宫颈癌根治术后反射性尿闭1例报告并文献复习

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吉林大学学报（医学版） 2015年第4期41卷 854-857页

作者：张静文郑连文常笑语刘永正高利伟付璐璐徐影吉林大学第二医院妇产科吉林长春130041 吉林大学白求恩医学部临床医学院

目的:探讨宫颈癌术后反射性尿闭的临床特点,并分析其诊断及治疗方法。方法:结合文献复习,回顾性分析本院收治的1例宫颈癌根治术后反射性尿闭患者的临床资料。该患者行宫颈癌根治术后69h无尿,血肌酐渐进性升高至620.7μmol·L-1。病程中... 详细信息

目的:探讨宫颈癌术后反射性尿闭的临床特点,并分析其诊断及治疗方法。方法:结合文献复习,回顾性分析本院收治的1例宫颈癌根治术后反射性尿闭患者的临床资料。该患者行宫颈癌根治术后69h无尿,血肌酐渐进性升高至620.7μmol·L-1。病程中对该患者进行补液、纠正水和电解质紊乱、利尿、解痉治疗,同时行输尿管支架植入术,并给予药物降压等积极治疗。结果:患者于宫颈癌根治术后第69小时开始有尿液排出,肾功能逐渐恢复正常。治疗后随访4个月,患者排尿正常,肾功能亦完全正常。结论:反射性尿闭在临床上罕见,但易致急性肾损伤,且容易误诊。早期诊断通常可使反射性尿闭患者在经药物或手术治疗后顺利得以救治。

关键词：宫颈肿瘤/诊断宫颈肿瘤/外科学子宫切除术反射性尿闭

Airside pressure drop characteristics of three analogous serpentine tube heat exchangers considering heat transfer for aero-engine cooling

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Chinese Journal of Aeronautics 2022年第12期35卷 32-46页

作者： Yinlong LIU Guoqiang XU Yanchen fu Jie WEN Shaoshuai QI lulu LYU Research Institute of Aero-engine Beihang UniversityBeijing 100083China National Key Laboratory of Science and Technology on Aero-engine Aero-thermodynamics Beihang UniversityBeijing 100083China School of Energy and Power Engineering Beihang UniversityBeijing 100083China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310023China China Aerospace Aerodynamics Technology Research Institute Beijing 100074China AECC Commercial Aircraft Engine Co. Ltd.Shanghai 200241China

This study explores the design,analysis,and air pressure drop assessment of three analogous air–fuel heat exchangers consisting of thin serpentine tube bundles intended for use in high Mach number *** high speed flight,the compressor bleed air used to cool high temperature turbine blades and other hot components is too ***,aviation kerosene is applied to precool the compressor bleed air by means of novel air–fuel heat *** light and compact heat exchangers including dozens of in-line thin serpentine tube bundles were designed and manufactured,with little difference existing in aspects of tube pitches and outer diameters among three heat *** fuel flows inside a series of parallel stainless serpentine tubes(outer diameter:2.2,1.8,1.4 mm with 0.2 mm thickness),while the air externally flows normal to tube bundles and countercurrent with *** studies were carried out to investigate the airside pressure drop characteristics on isothermal states with the variation of air mass flow rates and inlet ***-isothermal measurements have also been performed to research the effect of heat transfer on pressure *** experimental results show that inlet temperatures have significant influence on pressure drops,and higher temperatures lead to higher pressure drops at the same mass flow *** hydraulic resistance coefficient decreases quickly with Reynolds number,and the descent rate slows down when Re>6000 for all three heat ***,the pressure drop on heat transfer states is less than that on isothermal states for the same average ***,the pressure drop through heat exchangers is greatly affected by attack angles and transverse pitches,and an asymmetric M-shaped velocity profile is generated in the crosssection of sector channels.

关键词： Aero-engine Heat exchanger Heat transfer Pressure drop Serpentine tube

Frictional resistance of supercritical pressure RP-3 flowing in a vertically downward tube at constant heat fluxes

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Chinese Journal of Aeronautics 2022年第9期35卷 117-128页

作者： Yinlong LIU Guoqiang XU Yanchen fu Jie WEN Geng GONG lulu LYU Research Institute of Aero-engine Beihang UniversityBeijing 100191China National Key Laboratory of Science and Technology on Aero-engine Aero-thermodynamics Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBeijing 100191China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310023China China Aerodynamics Research and Development Center Mianyang 621000China AECC Commercial Aircraft Engine Co. Ltd.Shanghai 200241China

Based on the demands of compact heat exchangers and micro cooling channels applied for aviation thermal protection, the flow resistance characteristics of aviation kerosene RP-3 were experimentally studied in a vertically downward circular miniature tube with an inner diameter of 1.86 mm at supercritical pressures and constant heat fluxes. A long and short tube method was used to accurately calculate the frictional pressure drop, and experimental conditions are supercritical pressures of 4 MPa, mass flow rates of 2–4 g/s(i.e., mass fluxes of 736–1472 kg/(m^(2)·s)), heat fluxes of 100–500 kW/m^(2), and inlet temperatures of 373–673 K. Results show that the sharp variations of thermophysical properties, especially density, have significant influences on frictional ***, the frictional pressure drop and the friction factor increase with increasing inlet temperatures, and this trend speeds up in the relatively high-temperature region. However, the friction factor has a sudden decline when the fuel outlet temperature exceeds the pseudo-critical *** frictional pressure drop and the friction factor basically remain unchanged with increasing heat flux when the inlet temperature is relatively low, but increase quickly when the inlet temperature is relatively high. Besides, a larger mass flux yields a higher pressure drop but does not necessarily yield a higher friction factor. Finally, an empirical friction factor correlation is proposed and shows better predictive performance than those of previous models.

关键词： Aviation kerosene RP-3 Constant heat flux Empirical correlation Friction factor Supercritical pressure Vertical tube

孕产期生育舞蹈干预对母婴结局影响的Meta分析

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齐齐哈尔医学院学报 2023年第8期44卷 744-750页

作者：符路路张传英朱宇解艺璇魏巍王玥安徽中医药大学护理学院安徽合肥230012

目的系统评价孕产期生育舞蹈对母婴结局的干预效果。方法在PubMed、Cochrane Library、Embase、Clinical trials、Web of Science、中国知网、万方数据知识服务平台、中国维普全文数据库和中国生物医学文献数据库搜索与生育舞蹈干预分... 详细信息

目的系统评价孕产期生育舞蹈对母婴结局的干预效果。方法在PubMed、Cochrane Library、Embase、Clinical trials、Web of Science、中国知网、万方数据知识服务平台、中国维普全文数据库和中国生物医学文献数据库搜索与生育舞蹈干预分娩相关的随机对照试验,检索时限为建库至2022年3月,采用RevMan5.4软件进行Meta分析。结果共纳入14项随机对照研究,包括2404例产妇。Meta分析结果显示,与常规产科保健相比,生育舞蹈能有效降低剖宫产率[OR=0.30,95%CI(0.24,0.37),P<0.00001];降低新生儿窒息率[OR=0.16,95%CI(0.09,0.32),P<0.00001]与新生儿早产率[OR=0.32,95%CI(0.18,0.58),P<0.001];缩短第一产程时长[SMD=-4.06,95%CI(-5.31,-2.82),P<0.00001]与总产程时长[SMD=-5.58,95%CI(-7.59,-3.57),P<0.00001];有效缓解分娩疼痛[MD=-0.53,95%CI(-0.98,-0.08),P<0.05]。结论生育舞蹈可有效降低剖宫产率;明显降低新生儿窒息和早产的风险;显著缩短第一产程及总产程时长;有效减轻分娩疼痛,提高分娩舒适度。因纳入文献样本量及质量限制,本结论还需更多大样本、高质量的随机对照试验进一步验证。

关键词：分娩生育舞蹈剖宫产 Meta分析随机对照试验

Characterization and acid-mobilization study for typical iron- bearing clay mineral

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Journal of Environmental Sciences 2018年第9期30卷 222-232页

作者： Zhenzhen Wang Rui Li lulu Cui Hongbo fu Jun Lin Jianmin Chen Shanghai Key Laboratory Atmospheric Particle Pollution and Prevention Department of Environmental Science and EngineeringFudan University Shanghai 200433 China Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science and Technology Nanjing 210044 China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092 China Key Laboratory of Nuclear Analysis Techniques Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800 China

In this study, iron speciation in five standard clay samples was characterized. Iron mobilization from these clays was then measured in acidic media. For comparison, a commercially available Arizona test dust （ATD） was also observed. The results showed that the free-Fe contents of clays were commonly lower than that of dust aerosols. The components of clays were dominant by the structural Fe held in the aluminosilicate lattice. The iron solubility of the clays were in the order of KGa-2 〉 SWy-2 〉 CCa-2 〉 IMt-2 〉 NAu- 2. Based upon the M6ssbauer spectrum and transmission electron microscopy （TEM） analysis, the Fe（Ⅱ） fraction and the Fe/Si ratio of clay particles changed after dissolution, suggesting the total Fe solubility depended on the Fe atom states existing within the aluminosilicate lattice. The Fe in KGa-2 and SWy-2 was most likely substituted for alkaline elements as the interlayer ions held by ionic bonds in the aluminosilicate, which are more liable to dissolution. However, the Fe in NAu-2 was more likely to be bound by strong covalent bonds in aluminosilicate mineral, which is less soluble. The much highly soluble Fe in ATD was not only linked to the dissolution of an appreciable fraction of Fe（Ⅱ）, but also could be attributed to the fact that the Fe bonds in the clay fraction of ATD were mainly present as ionic bonds. The TEM images showed that reacted clay particles displayed less aggregate particles, with nanoparticle aggregates and the Fe/S-rich tiny particles attached to the remains.

关键词： Clay particles Dust Iron mobilization Marine primary productivity

The 2-axis stress component decoupling of {100} c-Si by using oblique backscattering micro-Raman spectroscopy

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Science China(Physics,Mechanics & Astronomy) 2020年第9期63卷 51-57页

作者： DongHui fu XiaoYong He lulu Ma HuaDan Xing Tian Meng Ying Chang Wei Qiu Tianjin Key Laboratory of Modern Engineering Mechanics Department of MechanicsTianjin UniversityTianjin 300350China Department of Mechanical Engineering Lamar UniversityBeaumont TX 77710USA Department of Electrical and Computer Engineering University of DelawareNewark DE 19711USA

With the application of strain engineering in microelectronics,complex stress states are introduced into advanced semiconductor ***,there is still a lack of effective metrology for the decoupling analysis of the complex stress states in semiconductor *** paper presents an investigation on the 2-axis stress component decoupling of{100}monocrystalline silicon(c-Si)by using oblique backscattering micro-Raman spectroscopy.A spectral-mechanical model was established,and two practicable methods for actual stress decoupling analyses were *** verification experiments demonstrated the correctness and applicability of the methods proposed in this paper.

关键词： {100}c-Si stress component decoupling oblique backscattering micro-Raman spectroscopy

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超声局部介入治疗下肢深静脉血栓效果观察

中国继续医学教育 2020年第3期12卷 56-58页

作者：夏从乐肖松甲袁婷陈珊珊孟茹陈琳付路路湖北省松滋市人民医院超声影像科

目的探讨和观察超声影像在局部溶栓介入治疗下肢深静脉血栓的应用效果。方法选择2018年2月-2019年2月在我院诊疗的48例行局部溶栓介入治疗下肢深静脉血栓患者作为研究对象,所有患者均采取局部插管溶栓治疗,并通过超声影像引导,使用微泵... 详细信息

目的探讨和观察超声影像在局部溶栓介入治疗下肢深静脉血栓的应用效果。方法选择2018年2月-2019年2月在我院诊疗的48例行局部溶栓介入治疗下肢深静脉血栓患者作为研究对象,所有患者均采取局部插管溶栓治疗,并通过超声影像引导,使用微泵向导管中无间断注入尿激酶,然后在24 h之后对患者行超声监测。结果通过超声影像定位,穿刺针均较为顺利的进入到患者的腘静脉,一次穿刺成功率为100%;通过超声引导,所有溶栓导管均置入指定位置,超声引导均获得成功,超声引导成功率为100.00%;术后46例患者痊愈,2例好转,治愈率达95.83%,总有效率可达100.00%。结论超声影像可在局部溶栓介入治疗下肢深静脉血栓过程中得到有效应用,应用价值良好。

关键词：超声影像局部溶栓介入治疗下肢深静脉血栓局部插管溶栓效果